susceptibility assay
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2021 ◽  
Vol 2021 ◽  
pp. 1-3
Author(s):  
Alireza Firooz ◽  
Ensieh Lotfali ◽  
Mahsa Fattahi ◽  
Maryam Fattahi ◽  
Akram Miramin Mohammadi ◽  
...  

A 26-year-old male patient referred to our center with a history of extremely itchy crusted skin lesions in his groins for one year. Moreover, his friend, a 25-year-old male, also developed similar lesions in the groin after using the shared pool, whose condition also did not improve with similar treatment. A regular mycology test (direct and culture test) was performed, as well as molecular examination. The antifungal susceptibility assay to terbinafine, itraconazole, posaconazole, fluconazole, and voriconazole was conducted according to the Clinical and Laboratory Standards Institute M38 third ed. The sequencing study identified T. tonsurans as the causative organism in both patients. The abovementioned organism isolated from both patients displayed resistance against terbinafine and fluconazole (MIC ≥ 4 µg/ml and MIC ≥ 8 µg/ml, respectively). Moreover, the susceptibility of both subjects to posaconazole (0.313 µg/ml), voriconazole (0.25–0.0625 µg/ml), and (1 µg/ml) itraconazole increased. The present report aimed to emphasize the increase in antifungal resistance and a demand for antifungal stewardship, to control this public health threat.


Elkawnie ◽  
2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Mashuri Masri ◽  
Cut Muthiadin ◽  
Masita Masita ◽  
Tri Cahyanto ◽  
Lianah Lianah ◽  
...  

Abstract: Tuberculosis (TB) is a contagious infectious disease caused by Mycobacterium tuberculosis. 10 million people suffer from TB Every year. Although TB is a preventable and treatable disease, 1.5 million people die every year due to TB. Alternative treatments continue to be pursued, and treatment with the latest TB drugs that are continuously being encouraged. Black cumin (Nigella sativa) seed contains essential oils with active compounds such as thymohydroquinone, Oleoresins, flavonoids, alkaloids, saponins, tannins, and terpenoids that act as antibacterial drugs. This study aims to determine the sensitivity of  N. sativa seed extract in inhibiting the growth of  M. tuberculosis strain H37RV and MDR-TB (Multidrug Resistance-TB). This research using Microscopic-Observation and Drug-Susceptibility Assay (MODS) method. Extraction of N. sativa was carried out by the maceration method using 70% methanol as a solvent. The results showed that the M. tuberculosis strain H37RV and MDR-TB were sensitive to N. sativa extract at concentrations of 5 and 10% but resistant to N. sativa extract at concentrations of 1 and 3%.Abstrak: Tuberkulosis (TB) adalah penyakit menular yang disebabkan oleh Bakteri Mycobacterium tuberculosis. Penyakit ini menimbulkan dampak kematian yang cukup mengkhawatirkan.  Penyakit tersebut dapat dicegah dan diobati. Salah satu sumber pengobatannya menggunakan biji jintan hitam (Nigella sativa) yang mengandung minyak atsiri dengan senyawa aktif seperti timohidrokuinon, oleoresin, flavonoid, alkaloid, saponin, tanin, dan terpenoid yang berfungsi sebagai obat antibakteri. Penelitian ini bertujuan untuk mengetahui sensitivitas ekstrak biji N. sativa dalam menghambat pertumbuhan M. tuberculosis strain H37RV and MDR-TB (Multidrug-Resistance-TB). Penelitian ini menggunakan metode Microscopic-Observation and Drug-Susceptibility Assay (MODS). Ekstraksi N. sativa dilakukan dengan metode maserasi menggunakan pelarut metanol 70%. Hasil yang diperoleh menunjukkan bahwa bakteri M. tuberculosis strain H37RV dan TB-MDR, kedua  strain tsb sensitif terhadap ekstrak N. sativa konsentrasi 5 dan 10%,  tetapi resisten terhadap  ekstrak N. sativa konsentrasi 1 dan 3%.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
B Amir ◽  
Y Javed ◽  
S Hanif ◽  
M Tahir ◽  
MA Rana ◽  
...  

The development of low-cost, fast, and reliable methods for detecting Mycobacterium tuberculosis (MTB) infection and drug susceptibility is critical for tuberculosis control. The new microscopic examination of liquid drug susceptibility assay (MODS) examines early MTB colonies in a liquid medium, which permits for more convenient diagnosis and testing of drug susceptibility. The sensitivity of MODS (91%) was superior as compared to the sensitivity of different culture methods (92%). The MGIT and MODS were used to monitor tuberculosis-positive sputum samples for isoniazid and rifampin susceptibility. Concordance between MODS and MGIT was found in 89 percent of cases. MODS are the fastest method used for diagnostic and susceptibility testing (median, 10.0 or 9 days). MODS is a fast, low-cost, responsive, and particular method for detecting and testing MTB susceptibility; it is specifically well-suited utilize in growing countries with high infection rates and a growing number of multidrug-resistant cases.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Abdi Wira Septama ◽  
Eldiza Puji Rahmi ◽  
Lucia Dwi Antika ◽  
Rizna Triana Dewi ◽  
Amit Jaisi

Abstract The emergence of antibacterial resistance has significantly increased. Pseudomonas aeruginosa is associated with nosocomial infection and difficult to control. Artocarpin, a flavonoid from Artocarpus heterophyllus Lam. exhibits several pharmacological properties including antibacterial. The study was performed to evaluate interaction between artocarpin and antibiotics including tetracycline against P. aeruginosa. Its mechanism of action on membrane permeability was also investigated. Broth microdilution was conducted for the susceptibility assay. The interaction of artocarpin and antibiotics was evaluated using checkerboard method, the effect on alteration of membrane cell was investigated using bacteriolysis and the released of 260 nm materials. Artocarpin showed moderate to weak activity against the Gram-negative bacteria including P. aeruginosa with MIC values in the range of 31.25–250 μg/mL. A synergistic effect against P. aeruginosa was produced by the combination of artocarpin (31.25 μg/mL) and tetracycline (1.95 μg/mL) with FICI of 0.37. The time-killing assay showed that artocarpin enhance the antibacterial activity of tetracycline against P. aeruginosa by completely inhibiting the bacterial growth. Additionally, the mixture of artocarpin (31.25 μg/mL) and tetracycline (1.95 μg/mL) disrupted membrane permeability and lead to cell death. These results proposed that the combination of artocarpin and tetracycline may be used to overcome P. aeruginosa infection.


Author(s):  
Daiane Heidrich ◽  
Danielle Machado Pagani ◽  
Alessandra Koehler ◽  
Karine de Oliveira Alves ◽  
Maria Lúcia Scroferneker

Chromoblastomycosis (CBM) is a chronic subcutaneous infection caused by genera of melanized fungi: Fonsecaea, Cladophialophora, Phialophora, Exophiala and Rhinocladiella. Melanin is a virulence factor known to influence antifungal susceptibility. A specific inhibitor of melanin biosynthesis is tricyclazole. The aim of this study was to evaluate the effect of melanin inhibition on antifungal susceptibility of chromoblastomycosis agents and describe the susceptibility profile of some unusual CBM agents. Seventy-six clinical isolates, representing 13 species of the five main CBM agents genera, were studied. The antifungal susceptibility was performed according to the M38-A2 protocol of CLSI. In the melanin inhibition test, 16 mg/L of tricyclazole was added to the medium used in the inoculum preparation and the susceptibility assay. CBM agents were less susceptible to amphotericin B in comparison with azoles and terbinafine. The unusual species showed similar susceptibilities profiles to those of other species of the same genera. With tricyclazole exposition, MICs of terbinafine, posaconazole and itraconazole for Fonsecaea spp. significantly decreased (p<0,05). For Phialophora spp., this reduction was significative for posaconazole and itraconazole. For the other genera, there was a reduction in MICs of terbinafine and itraconazole, however, the statistical tests were not significant. Melanin inhibition can increase the antifungal susceptibility of most CBM agents to itraconazole and terbinafine, the main used drugs in the disease treatment. This increased susceptibility may open up new possibilities for therapy in refractory cases of CBM and/or caused by resistant fungal strains. Further studies are needed to confirm the same results in vivo.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sonal Girish ◽  
Suresh Kumar ◽  
Norhaniza Aminudin ◽  
Najihah Mohd Hashim

AbstractBlastocystis sp. infection, although many remain asymptomatic, there is growing data in recent studies that suggests it is a frequent cause of gastrointestinal symptoms in children and adults. This proposes that treatment against this infection is necessary however metronidazole (MTZ), which is the current choice of treatment, has expressed non-uniformity in its efficacy in combating this infection which has led to the study of alternative treatment. In our previous study, it was established that Tongkat Ali fractions exhibited promising anti-protozoal properties which leads to the current aim of the study, to further narrow down the purification process in order to identify the specific active compound promoting the anti-protozoal effect through HPLC analysis. Based on the data analysis and in-vitro susceptibility assay, the collected Tongkat Ali fraction that demonstrated anti-blastocystis property was shown to contain eurycomanone. Previous studies have suggested that there is a mechanism in Blastocystis sp. that regulates the apoptotic process to produce higher number of viable cells when treated. In reference to this, our current study also aims to investigate the apoptotic response of Tongkat Ali extract and eurycomanone across different subtype groups with comparison to MTZ. Based on our investigation, both Tongkat Ali extract and eurycomanone induced the high apoptotic rate however exhibited a reduction in viable cell count (p < 0.05) when compared to MTZ. This study suggests that there is potential in developing a standardized treatment regardless of subtype variations which makes Tongkat Ali extract a promising anti-protozoal treatment against all Blastocystis sp. subtype groups.


2021 ◽  
Vol 8 (1) ◽  
pp. 1-4
Author(s):  
Fatemeh Shafiei Seifabadi ◽  
Majid Baserisalehi

Background: Microorganisms have potent activity for transferring antibiotic-resistant genes with either chromosomally- or plasmid-mediated characteristics. The purpose of this study was to isolate Lactobacillus from different commercial products and evaluate their potential in antibiotic-resistant development. Chromosomally-or plasmid-mediated resistant genes were investigated as well. Methods: In total, Lactobacillus strains were isolated from 20 commercial dairy product samples such as cheese and yoghurt. The isolates were phenotypic and molecularly identified and their antibiotic-resistant properties were assessed by the disk-diffusion method. Finally, the plasmid-mediated antibiotic resistant characters of the isolates were evaluated by plasmid curing via evaluated temperatures and acridine orange methods. Results: Five strains Lactobacillus paracasei, L. rhamnosus, L. casei, L. plantarum, and L. fermentum were isolated different products. The results of the antibiotic susceptibility assay indicated that all strains were susceptible to amoxicillin and imipenem and resistant to ciprofloxacin and vancomycin. Furthermore, different responses were observed among the isolates against streptomycin and gentamicin. The evaluation of plasmid-mediated antibiotic resistance in the isolates revealed that streptomycin and gentamicin-resistant characters were of plasmid-mediated type in L. rhamnosus and L. plantarum strains. Conclusions: In general, our finding demonstrated that some commercial Lactobacillus strains harboured antibiotic-resistant genes. These genes can be located either in chromosome or plasmid group. Hence, the frequency of antibiotic-resistant pathogenic bacteria might be increased after consuming some dairy products because of the horizontal transfer of antibiotic-resistance genes among the bacteria.


2021 ◽  
Vol 22 (2) ◽  
Author(s):  
Edwin Alcantara ◽  
MARNELLE M. ATIENZA ◽  
LUIS CAMACHO ◽  
SRINIVAS PARIMI

Abstract. Alcantara EP, Atienza MM, Camacho L, Parimi S. 2021. Baseline susceptibility of Philippine Ostrinia furnacalis (Lepidoptera: Crambidae) populations to insecticidal Cry1A.105 and Cry2Ab2 proteins and validation of candidate diagnostic concentration for monitoring resistance. Biodiversitas 22: 956-960. This study estimated the baseline susceptibility of Ostrinia furnacalis populations from the Philippines, to purified insecticidal Cry1A.105 and Cry2Ab2 proteins and determined a diagnostic concentration (DC) through a validation experiment. The insect populations were collected from separate sites of corn farms in Northern and Central Luzon and in South Cotabato province of the island of Mindanao. Dose-response bioassays using artificial diet surface overlay method were conducted on eight populations. The bioassay results revealed that the LC50 of Cry1A.105 and Cry2Ab2 to O. furnacalis ranged from 0.03 ng/cm2 to 0.18 ng/cm2 and 1.40 ng/cm2 to 9.98 ng/cm2, respectively. The relative susceptibility ratios between the most susceptible and most tolerant populations were 6-fold for Cry1A.105 and about 7-fold for Cry2Ab2. The candidate diagnostic concentrations (DC) based on the LC99 were calculated using the baseline bioassay data for both Cry1A.105 and Cry2Ab2. The validation was performed on populations from the same locations used in the baseline susceptibility assay and a reference strain to produce at least 99% mortality for each protein. Data showed that populations tested with Cry1A.105 produced average mortality of at least 99% for the upper limit, while this was observed in the LC99 estimate for Cry2Ab2. The validated diagnostic concentration can be used for monitoring the resistance development of O. furnacalis exposed to Bt Corn, MON89034, in the Philippines.


Author(s):  
Le T Huong ◽  
◽  
Nguyen T Viet ◽  
Ly N Sam ◽  
Cao N Giang ◽  
...  

This paper described the chemical compositions and antimicrobial activity of the essential oils from the leaves and stem of Amomum rubidumLamxay & N. S. Lý, collected from Bidoup Nui Ba National Park, Lam Dong, Vietnam. The essential oils were obtained by hydrodisitllation method while antimicrobial activity was evaluetd by microdilution broth susceptibility assay. The main constituents of the leaf essential oil were identified as 1,8-cineole (37.7%), -3-carene (19.5%) and limonene (16.3%) while -3-carene (21.9%), limonene (17.8%) and β-phellandrene (14.6%) dominated in the stem essentialoil. The leaf and stem essential oils displayed stronger inhibition of Pseudomonas aeruginosawith MIC of 25 μg/mLand 50 μg/mLrespectively. The stem essential oil was active against Candida albicans(MIC, 50 μg/mL) while both essential oils inhibited the growth of Fusarium oxysporum(MIC 50 μg/mL). This is the first report on chemical constituents and antimicrobial activity of the essential oils of A. rubidum.


2020 ◽  
pp. AAC.01338-20
Author(s):  
S. O. Abd Algaffar ◽  
A Verbon ◽  
W. W. J. van de Sande ◽  
S. A. Khalid

We here present an in vitro susceptibility assay for Madurella mycetomatis hyphae using resazurin for endpoint-reading. Using this assay, reproducible minimal inhibitory concentrations (MICs) were obtained for amphotericin B, itraconazole, voriconazole, posaconazole, terbinafine and micafungin. Results were comparable with XTT-based susceptibility assay. Lowest MICs were obtained for itraconazole and posaconazole (MIC50 of 0.016 μg/mL) followed by voriconazole (MIC50 of 0.063 μg/mL). Amphotericin B, micafungin, and terbinafine appeared much less effective.


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